This invention relates to gas discharge panels for use in displaying alpha-numeric information, advertising displays, television images and the like.
Most prior art gas discharge panels have been unable to complete successfully with cathode ray tubes in generating visual images. This has been true, for the most part, because of the inability of gas discharge panels to produce images which are as bright as the images generated by cathode ray tubes (CRT's). In addition, most gas discharge panels require complex driving circuitry since they usually drive one full row or line of characters or picture elements at a time (line-at-a-time operation) in order to generate a brighter display. This line-at-a-time operation requires circuitry for storing one complete row of information while simultaneously displaying another row of information. Cathode ray tubes, on the other hand, are usually driven point-at-a-time and do not therefore need the storage circuitry which the line-at-a-time gas discharge displays need.
This lack of brightness and resultant inability of most priorr art gas discharge displays to be operated in a point-at-a-time mode has made it difficult for such displays to complete effectively with cathode ray tubes, particularly in the area of reproducing television images.
Although some gas discharge panels have been used to reproduce television images, they have been operated in a line-at-a-time mode wherein all picture elements of a line or row of picture information are simultaneously energized for approximately 52 microseconds. But even operating in this line-at-a-time mode, most prior gas discharge panels are unable to generate images as bright as those possible with CRT's.
A gas discharge panel operated in a point-at-a-time mode has even less chance of generating a competitively bright image since it would energize only one picture element at a time, thereby reducing the "ON" time of each picture element by a factor of approximately 500. Of course, a corresponding reduction in the image brightness would follow and, for prior art gas discharge panels, would result in a reproduced image which would be far too dim for practical use.